Between July 2010 and December 2011, Dr. Donald Berwick was head of the Centers for Medicare and Medicaid Services, the agency that runs the government's health insurance programs. In a sane world, he would be still. But Senate Republicans refused even to let his confirmation come up for a vote, and he had to step down after 18 months. (President Obama had installed Berwick at CMS on an interim basis through a recess appointment.) A pediatrician by training and a widely respected expert in health care policy, Berwick should have been a lock for the CMS job. But he was a backer of Obamacare; a believer in data and science; a proponent of universal health care; and, worst of all, an admirer of Britain's government-run National Health Service. In other words, he was anathema to congressional Republicans. So that was that.

A professor of health policy at Harvard and a newly-minted fellow at Center for American Progress, a liberal think tank, Berwick is a widely-admired leader in the field of healthcare improvement, having devoted much of his life to figuring out, via rigorous empirical study, how best to improve care and lower costs. Rolling Stone got him on the phone to talk about this week's healthcare hearings at the Supreme Court, the importance of Obamacare, and the future of reform.

A lot of people think the Supreme Court hearings went badly for the pro-Obamacare side. How about you?

The tone of the questioning was often pretty aggressive, of course, but you can't always tell much from that. There were numerous lower-court cases where we saw the same thing: aggressive questioning by judges who, with only a couple of exceptions, later upheld the law. I think that could happen in this case, too.

In the broadest sense, what do you see at stake here?

I think the Affordable Care Act is a really important law. It's designed to provide better care for individuals, better health for communities, and lower costs all around, and it's a massive step forward on all those measures. The law is already really positive for millions of Americans, and when it takes full effect [starting in 2014], it's going to help tens of millions, in terms of coverage, cost, and quality of care. But the most important aspect of the law, to me, is the progress it implies toward enshrining health care as a human right in this country.

What benefits are people seeing under the law right now that would be taken away in case of repeal?

We have 2.5 million people under 26 who are now covered under their parents' insurance policies; they would lose that coverage. Millions of seniors are getting annual "wellness visits" and preventive care that weren't covered before; they would lose that. Children can’t now be denied coverage because of preexisting conditions; that would change. We'll begin to see results very soon in improved patient safety, which could be reversed.

A key rationale for reform was that it would bring spiraling health care costs under control. Have we seen improvements there?

We have a system perfectly designed to achieve ever-escalating costs through lots of activities – procedures, tests, prescriptions, diagnoses – that don't help patients. The law shifts the attention of providers toward doing things that help patients and not trying to make a lot of money doing things that don't help patients. I suspect we'll begin to see some of the initial savings coming into play in 2013 and 2014. Will it be fast enough? I don't know; but the right first steps are in place.

There was a lot of discussion this week over whether the law could survive if the Court were to rule against the individual mandate, which requires that everyone buy health insurance or pay a penalty. What’s your take on that?

The mandate is an extremely important element of the fabric of the intent of the law, which is to make sure that coverage becomes as close to universal as it can. Once you take it away, there's a risk that other elements – guaranteed issue and community rating – will unwind. There are those who say it might be possible to provide enough subsidy to continue to attract people who might otherwise defer insurance until they were sick. But I’m not so sure; I think the law was well conceived and well constructed, and without the mandate it starts to look fragile.

And then what?

If the law was taken away in its entirety, then my question is: Well, what's your plan? It would be a concession to a status quo, to a system that costs too much and achieves too little. People who feel they really care about this but don't like the law would have the duty to suggest something else.

But haven’t Republicans suggested something else – among other things, cutting Medicare and privatizing it, at least in part?

That’s not going to change delivery or reduce costs; it just takes things away, minimizing benefits to the point where you're not really meeting people’s needs. Making Medicare in part a voucher program is literally shifting the buck to people, in many cases to the people least able to afford it. Plus, it guarantees higher administrative costs. After all, Medicare operates at far lower administrative costs. To me, it's a way to dismantle a pretty successful program.

Given the political environment – polarization, gridlock, overheated rhetoric – it’s hard to see a positive alternative emerging anytime soon.

How to rescue and fix the American healthcare system is not an easy problem, with or without the Affordable Care Act. The best people, no matter what their political catechism happens to be, need to be thinking together and working together. The habit of dialogue and exploration and even civility is in retreat right now, and that's very unfortunate. Plus, the cycle times for American public policy are very long; it takes our country a decade or longer to regroup to address matters of such importance to the public. So I think we could find ourselves in a long period of costly paralysis if the law goes away. The problems it was created to address don't go away. President Whoever, and whatever Congress is elected, will face exactly the same problems.